Polyesters which are made to contain units derived from a sulfodicarboxylic acid are well known, primarily for their use in fibers that can be readily dyed by basic dyes. Such polyesters are typically highly crystalline and also do not contain a sufficient number of units derived from a sulfodicarboxylic acid to be water soluble.
Polyesters that contain a sufficient number of units derived from a sulfodicarboxylic acid to make the polyester water soluble, water dispersible, water dispellable, or water dissipatable are also known. U.S. Pat. Nos. 4,052,368, 4,300,580, and 4,304,901, for example, disclose polyesters rresulting from the reaction of aromatic dicarboxylic acids and/or aromatic dicarboxylic acids having a sulfonate group, with aliphatic diols. All of the examples of these patents illustrate the preparation or use of polyesters that, although water-soluble or dispersible, are crystalline or which would crystallize on subjecting the polyester to annealing conditions. Of the three patents cited above, U.S. Pat. Nos. 4,052,368 and 4,300,580 list aromatic dicarboxylic acids which can be used to prepare water-soluble or water-dispellable polyesters, and include in the list o-phthalic acid. They do not disclose the attainment of an amorphous product, however. It is my belief that neither of the above-cited patents, nor any other art of which I am aware, disclose film-forming, water-soluble polyesters that are amorphous and noncrystallizable even when maintained under annealing conditions.